首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Recently,severalkindsoftotalsyntheticmethodsfornaturallyoccurringfuranoidfattyacids(F-acids)whichhavemanybiologicalactivities1havebeendeveloped2.Inthepresentpapertheauthorswishtoreportanewsimplerouteofsynthesizing9-(5-pentyl-carbomethoxyheptyl)triphenylphosphoniumbromideinthepresenceofpotassiumcarbonateandl,2-butyleneoxideinanunexpectedlylowyield(34%),mainlyduetotheextremelyunstablecharacterof2inbasicconditions,especiallyforstrongbaselikesodiummethoxidewhichgaverisetoconsiderableresinification…  相似文献   

2.
Morpholinium 5-arylcarbamoyl-3-cyano-6-methyl-4-(5-methyl-2-furyl)-1,4-dihydropyridine-2-thiolates have been obtained by the interaction of enamines of acetoacetanilides with 5-methyl-2-furfurylidenecyanothioacetamide. Alkylation of the salts gives thioethers and oxidation gives the corresponding substituted pyridine-2(1H)-thiones. The structure of 2-allylthio-3-cyano-5-(2-methoxyphenylcarbamoyl)-6-methyl-4-(5-methyl-2-furyl)-1,4-dihydropyridine was studied by X-ray crystallographic analysis. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 51–58, January, 2006.  相似文献   

3.
研究了新合成试剂4-(5-硝基-2-吡啶偶氮)-1,3-二氨基苯(5-NO2-PADAB)与铑(Ⅲ)的显色反应.结果表明,在pH 3.3~4.7的乙酸-乙酸钠缓冲介质中,5-NO2-PADAB与铑形成2∶1的紫红色络合物,其最大吸收波长位于524 nm.该络合物在1.2 mol/L HClO4介质中可质子化转变为另一种型体的紫蓝络合物,最大吸收波长红移至580 nm,其表观摩尔吸光系数提高至1.52×105 L·mol-1·cm-1,以EDTA为掩蔽剂,大量常见金属离子不干扰测定.铑含量在0~0.8 μg/mL内符合比尔定律.所拟方法可应用于催化剂中微量铑的测定.  相似文献   

4.
The oxidation of 2-acetyl-5-methyl-4-R-furans (R = H, NO2) by selenious acid was studied. Derivatives substituted at the C=O groups of the corresponding glyoxals were obtained. The nitration of 2-(5-methyl-2-furyl)quinoxaline was carried out at C(4'). Oxidative splitting of the -nitrofuryl group occurs at the C(4)-C(5) and C(5)-O bonds.  相似文献   

5.
Esters and amides of 2,2-dichloro-3-(2-furyl)-3-hydroxypropionic acid were prepared by the reaction of furfural with dichloroacetic acid derivatives under the conditions of the Darzens condensation. The structures of the reaction products were confirmed by their1H NMR and IR spectra and chemical transformations.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1444–1448, August, 1994.  相似文献   

6.
The electrophilic reactions (nitration, bromination, hydroxymethylation, formylation, acylation) and radical substitution reactions (nitration, arylation) of 2-(2-furyl)benzothiazole have been studied. It was found that all of the reactions occur at position 5 of the furan ring. Only nitration in PPA gave the 5',6-dinitro derivative. Quantum-chemical calculation data for the electron density distribution in the neutral and protonated 2-(2-furyl)benzothiazole molecules are given. Dedicated to Boris Aleksandrovich Trofimov on his 70th jubilee. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1331–1338, September, 2008.  相似文献   

7.
Pd(OAc)2 in combination with tri(2-furyl)phosphine and methanesulfonic acid is an efficient catalyst for the alkoxycarbonylation of 1-alkynes. Fairly good reaction rates are obtained under mild conditions (50–80°C and P(CO)=20 bar) with high regioselectivity (ca. 95%) towards the formation of 2-substituted acrylic ester.  相似文献   

8.
Ethyl α-cyano-β-(p-fluorophenyl)-β-(2-furyl)propionate was obtained by the condensation of ethyl α-cyano-β-(2-furyl)acrylate with p-fluorophenylmagnesium bromide. Its deethoxycarbonylation led to β-(p-fluorophenyl)-β-(2-furyl)propionitrile. Reduction of the nitrile with lithium aluminum hydride gave γ-(p-fluorophenyl)-γ-(2-furyl)propylamine. Some transformations of the latter were studied. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 503–509, April, 2006.  相似文献   

9.
A series of 2,4,5-triaryl substituted 1H-pyrazol-3(2H)-ones,as ALK5 inhibitors,were desigened,synthesized and evaluated in vitro.Most compounds exhibited noticeable ALK5 inhibition activities at 1 μmol/L and displayed no significant cytotoxicities at 30 μmol/L.  相似文献   

10.
本文研究了2-(6-硝基-2-苯并噻唑偶氮)-5-二甲氨基苯甲酸(6-NO_2-BTAMB)与铜的显色反应。结果表明,在pH2.0~4.5的乙醇水溶液中6-NO_2-BTAMB与铜形成一种稳定的蓝绿色络合物,其最大吸收波长位于650nm处,表观摩尔吸收系数为7.75×10~4L·mol~(-1)·cm~(-1),络合物的组成为6-NO_2·BTAMB:Cu=1:1,铜浓度在0~10μg/10ml范围内服从比尔定律。该方法具有良好的选择性和灵敏度。在氟化铵和硫脲存在下,利用差减法,可直接测定含微量镍和钴的镁、铝合金中的铜,结果满意。  相似文献   

11.
新手性源5-(l-孟氧基)-3-溴-2(5H)-呋喃酮的合成和结构   总被引:7,自引:0,他引:7  
黄慧  陈庆华 《化学学报》1999,57(5):538-540
文中深入研究了5-(l-孟氧基)-3-溴-2(5H)-呋喃酮新手性源(5a)的合成方法及其不对称合成反应。5a不仅制备方法简便,光学纯度单一,而且它作为稳定的Michael受体,可与碳、氧、氮、硫等不同的亲核试剂发生串联的Michael加成/分子内亲核取代反应,制备得到含有多个手性中心的双环[3.3.0^3^,^7]-5-辛烯类化合物、双环[3.1.0^3^,^5]-己烷类化合物和螺-环丙烷类化合物。本文报道了该手性呋喃酮5a的合成和构型测定。  相似文献   

12.
A series of diorganotin(IV) and triorganotin(IV) compounds of the type [R2Sn(pca)2ClSnR3]2 (RPhCH21, 2-ClC6H4CH22, 2-FC6H4CH23, 4-FC6H4CH24, 4-CNC6H4CH25, 4-ClC6H4CH26, 2,4-Cl2C6H3CH27; Hpca2-methylpyrazine-5-acid), [(nBu)3Sn(pca)]8, [(CH3)2Cl2Sn(pca)Sn(CH3)2(pca)]9, {[(nBu)2Sn(pca)]2O}210 and {[Ph2Sn(pca)]3O2[Ph2Sn(OCH3)]} 11 have been obtained by reactions of 2-methylpyrazine-5-acid with triorganotin(IV) chloride, diorganotin(IV) dichloride, and diorganotin(IV) oxide. All compounds were characterized by elemental, IR, and NMR spectra analyses. The crystal structure of compounds 1, 8-11 were determined by X-ray single crystal diffraction, which revealed that compound 1 was tetranuclear macrocyclic structures with seven-coordinate and five-coordinate tin atoms, compounds 8 and 9 were polymeric chain structures with five-coordinate and seven-coordinate tin atoms, compounds 10 and 11 were monomeric structures with six-coordinate and five-coordinate tin atoms.  相似文献   

13.
鲍霞  张小玲 《分析化学》2006,34(4):529-532
金属离子、有机溶剂、缓冲介质与杂环偶氮苯甲酸类试剂之间存在一定的超分子作用,有机溶剂及缓冲介质的浓度和种类对显色反应的灵敏度有很大的影响。据此,建立了2-(6硝-基-苯并噻唑)偶氮-5二-甲氨基苯甲酸(6-NO2-BTAMB)与镍显色反应新体系。在乙醇存在时,6-NO2-BTAMB在(CH2)6N4-HC l缓冲体系中可与镍形成稳定的蓝绿色络合物,λm ax=650 nm,ε650=1.80×105L.mol-1.cm-1,在0~0.4 mg/L镍范围内符合比尔定律。方法用于纯镁、模拟合金样中微量镍的测定,结果令人满意。  相似文献   

14.
<正>Four novel 5-substituted pyridine-2(1H)-one derivatives were designed and synthesized by using addition-elimination reactions.The structures of these novelly synthesized compounds were verified by ~1H NMR,ESI-MS and single crystal X-ray diffraction.Furthermore,all four compounds(most notably compound 7a) were found to be highly efficient against hepatitis B virus (HBV) in cultured HepG2 2.2.15 cell,making them promising drug candidates for potential bioactive molecule against hepatitis B.  相似文献   

15.
黄敏  黄慧  陈庆华 《有机化学》2000,20(1):64-71
研究了新的手性试剂,5-(l-孟氧基)-3-溴-呋喃酮(5a)的合成及其与亲核性醇发生的串联不对称双Michael加成/分子内亲取代反应。通过此反应,一举生成了四个新的手性中心,得到了一般方法难以合成的含有多个手性中心的丁内酯并螺-环丙烷类化合物8a~8d。详细报道了8a~8d的合成方法以及它们的[α]、IR、UV、^1^HNMR、^13^CNMR、MS、元素分析等结构分析数据。此不对称双Michael加成/分子内亲核取代反应可以为某些新的光学活性螺-环内丙烷类化合物以及某些复杂结构的分子提供合成策略。  相似文献   

16.
The basic structural framework of lamellarin alkaloids, 8,9-dihydro-6H-chromeno[4′,3′:4,5]pyrrolo[2,1-a]isoquinoline derivatives, has been obtained in good yields via Grob synthesis between 3-nitro-2-(trifluoromethyl)-2H-chromenes and 1-methyl-3,4-dihydroisoquinolines in refluxing isobutanol. In the case of 1-benzyl-3,4-dihydroisoquinolines, a dynamic NMR effect was observed in the 1H and 19F NMR spectra of the products as a result of restricted rotation about the single bond linking the benzene ring and the heterocyclic system. When the reaction was carried out with 3-nitro-2-(trichloromethyl)-2H-chromenes in toluene at room temperature, only Michael adducts, as a mixture of two diastereomers, were isolated.  相似文献   

17.
李新芝  司宗兴 《有机化学》2002,22(3):178-182
1-(2-呋喃甲酰基)-4-芳基氨基硫脲经过环化反应,制备了一系列新的化合 物3-(2-呋喃基)-4-芳基-1,2,4-三唑啉-5-硫酮类化合物,并通过元素分析和 IR,^1H NMR等波谱数据确证了上述化合物的结构。初步的生物活性实验表明其中 有些化合物的具有非常好的植物生长调节活性。  相似文献   

18.
Fifteen novel (3-chloro-5-(trifluoromethyl)pyridin-2-yloxy)phenyl containing Baylis-Hillman adduct derivatives were designed and synthesized. Evaluation of their biological activities showed that methyl 2-((3-(3-chloro-5-(trifluoromethyl)pyridin-2-yloxy)phenoxy)(phenyl)methyl)acrylate (2g) exhibited efficient broad-spectrum fungicidal activity, with 100% control of wheat powdery mildew and cucumber downy mildew and 98% control of cucumber anthracnose at 400 g ai/ha. Some of the other title compounds 2, 3 and two Baylis-Hillman bromide intermediates (11a, 11b) had moderate to good fungicidal activity.  相似文献   

19.
本文采用新试剂2-(5-硝基-2-吡啶偶氮)-5-二乙氨基苯酚(5-NO_2-PADAP)为柱前衍生试剂,不需对离子试剂,用含40mmol/L 的 pH6.0的乙酸-乙酸钠缓冲溶液和10~(-4)mol/LEDTANa_2的甲醇-水溶液(67.5:32.5)为流动相,在 ODS 柱上,20min 内 HPLC 测定了 Fe(Ⅲ)、CO(Ⅱ)和 Ni(Ⅱ)的5-NO_2-PADAP 的络合物,这是同类衍生试剂中最简单流动相体系。当信噪比 SNR=2时,检出限分别为0.17、0.17和0.09ng/ml。是同类体系中灵敏度最高的。方法用于同时测定硝酸试剂和茶叶中的铁、钴和镍,结果良好。  相似文献   

20.
The present work reports an efficient one-pot synthesis of symmetrical pyridyl monoselenides by the reaction of bromo-/iodopyridines with the isopropylmagnesium chloride, iPrMgCl followed by quenching with selenyl chloride, SeCl2. The current methodology constitutes a convenient synthesis of bis(5-bromo-2-pyridyl) selenide (I), bis(2-bromo-5-pyridyl) selenide (II) and bis(2,5-dibromo-3-pyridyl) selenide (III) under cryogenic conditions requiring shorter time duration to give satisfactory yields. The hitherto unknown compounds have been characterized by elemental analysis and various spectroscopic techniques i.e., 1H NMR, 13C NMR, FT-IR, mass spectrometry and X-ray crystallography.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号